Dog.



C-. A. PALMGREN.

DOG. APPLICATION FILED JAN. II. 1915' Patented Nov. 2, 1915.

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DOG.

APPLICATION FILED JAN-[1,1915- Patented Nov. 2, 1915.

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1 1s a rear GlGVfLtlOILOf my im-y CARL A. rnLMGItEnOr sourn OHIOAGO, ILLINOIS, ASSIGNOR To srnnL ART TOOL COMPANY, OF oI Io'AGo, ILLINOIS, A CORPORATION OF ILLINOIs.

DOG.

Specification of Letters Patent.

Patented Nov. 2, 1915.

Application filed January 11, 1915. Serial No. 1,572.

' described and explained inthe specification and shown in theaccompa'nying drawings,

Flgure proved dog; Fig. 2 is a side elevation, looking from the right in Fig. 1; Fig. is a section on theline'3 of Fig. 1; Fig. 4: man ele vation of one of the jaws, looking from the right in Fig. 3; Fig.6. is, in the main, an elevation looking from the left in Fig. 3, but with the rear plate removed, the upper portion of the figure being a central trans verse section, and Fig. 6 is an elevation of the rearplate,"looking from the right of Fig. 3, the cam ring being shown superposed thereover in dotted lines.

Referring to the drawings, 7 is the rear plate of my dog. It is circular in contour, plain on its rear surface and centrally p erforated at 8. Surrounding the perforat on is a plurality of projections 9, extendlng forward from the front face of the rear plate. These projections have their peripheral surfaces perpendicular to the plane of the rear plate and their front surfaces parallel to said plane, each projection being thus, in geometrical terms, a prism. The faces of the projections are, roughly speaking, sector-shaped, the exact form being shown in the drawings and are spaced apart so as to form between them radial parallelwalled guide-ways 10. In these guide-ways lie aws 11, each having teeth 12 at its inner end and a beveled part 13 at its outer end..

The outer end of each dog is provided with a lip 1%- at the extremity of which is a for wardly extending hooked flange 15.

An operating ring 16 lies in front of the rear plate. The forward face of this ring is plain, its outer surface is provided with gear teeth 17 cut to cooperate with a worm, and the inner surface of the ring is provided with notches forming cam surfaces 18 equal in number to the jaws and so arranged that the rotation of the ring in a counter-clockwise direction, as viewed in Fig. 5, will force the jaws inward in an obvious manner. For the purpose of wlthdrawmg the jaws, the

rear face of the ring is cut away to receive t'helip let and grooved at 19 to receive the flanged hook on the lip 14 of the jaws. The grooves 19 are parallel to the cam surfaces 18, whereby a clockwise direction of the ring, as viewed in Fig. 5, will withdraw the jaws. g I I I .20 is-tlie front plate of the dog, plain on its frontside and centrally perforated at 21. It is provided at its outer periphery with a deep flange 22, the main portion of which is of the thickness ofthejaws, the operating a ring and the projections 9 on the rear plate,

7 plus a working clearance. The outer part of the flange 22 is provided with a further extension or shoulder 28 of the thickness of the rear plate. There is thus formed a completely closed annular structure, the front and outer periphery of which is formed by a front plate and its flange and the rear and inner periphery of which is formed by the rear plate and its projections 9, the spaces between the projections being filled by the jaws 11.

For the purpose of turning the operating ring, a tangential hole 24 is drilled through the flange of the front plate 22 so as to intersect the inner periphery of said flange. In the hole 24 is rotatably mounted a worm 25 keyed against longitudinal movement. The ends of the worm are provided with squared openings 26 which can be engaged by a wrench, and the entire worm is well within the hole made to receive it so that there are no projecting parts. For purposes of assembling the structure, the rear outer edge of the operating ring is out down to the plane of the gear teeth, as shown at 27 in Fig. 5.

In order to prevent rotation of the dog with reference to the back plate, there are provided two rearwardly projecting tapered pins 28 which are preferably oval in crosssection and which enter the structure so as to lie partly in the front and partly in the rear plate, as shown.

The operation of the structure will be very readily apparent from the description of its construction, the aws can be locked on any piece of work in a perfectly obvious manner and the dog will perform the usual functions of such devices. The structure is advantageous because it is cylindrical in form oflering no projecting parts upon which the op erator can be injured, and because 11; automatically centers itself with reference to the work and applies'its forceto the work in a a a symmetrical manner. I v- In driving with my dog'the arrangement should be such that the drivingforce ape plied'to the casing is in the direction that will tend to rotate the operating ring with reference to the jaws, which are retarded by the work, so as to tighten the jaws There is necessarily a certain lost-motion between the worm and the worm gear teethon siblein the details of the construction herein shown, and I do not intend to limit myself thereto, except as pointed out 1n the following claim, in which it is my intention to V claim all the novelty inherent in thedevice as broadly as is permitted by the state of the VWhat I claim as new a ndde s ire to'securej by'LettersPatent isz- V A dog comprising a disk-shaped hollow casing having a smooth cylindrical periphery interfitting therein, radially guided jaws within said casing movable toward andfrom' said aperture, an operating ring within said casing haying cams engagingsaidnjaws to advanceand retract them, a single means within said casing .operablefromr without for moving'said ring to adjust 's'aidljaws equally and simultaneously, and holding 40 Q pins locking said gether. In testim 'my hand. this NELLIE B. DEARBORN.

- and. a through central aperture, a face plate Copies of this patent may be obtained for five cents eaoh, byladdressingthe Commissioner l fateiits, i

i Washington, 13,0) V r i 

